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Positve and negative ground pedals

Started by Gledison, July 20, 2013, 01:56:00 PM

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Gledison

Hi everyone!
I understood that one can't connect a positive supply pedal with a negative one using the same PS.
Can I connect a negative supplied pedal running on batteries to a pedal using a positive PS ? how do you guys combine these pedals?
I've read that Fuzz pedals sound better using a positive supply. I want to build soon a Rangemaster and the layout by madbean is with a positive supply. By tonepad one can build using a negative supply. any experience on how this difference will affect the sound?
thanks a lot!
If i fart a lot,  it means that i'm a Gas expert ?

davent

Build the Rangemaster with the positive ground, there are so many unexplained gremlins that plague what in theory should work with the positive to negative switch,  it's just not worth the trouble. That said, if you have a NPN germanium go ahead with the negative ground Rangemaster.

The other option is to use charge pump like the Road Rage to get you the -9v rail. To me it's just simpler and easier to run the positive ground pedals from a battery as the current draw is so low, battery life is extremely long.

dave
"If you always do what you always did- you always get what you always got." - Unknown

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Gledison

Quote from: davent on July 20, 2013, 04:06:05 PM
Build the Rangemaster with the positive ground, there are so many unexplained gremlins that plague what in theory should work with the positive to negative switch,  it's just not worth the trouble. That said, if you have a NPN germanium go ahead with the negative ground Rangemaster.

The other option is to use charge pump like the Road Rage to get you the -9v rail. To me it's just simpler and easier to run the positive ground pedals from a battery as the current draw is so low, battery life is extremely long.

dave
Great! I will do this. what about connecting the pedals in series...can I connect if im using different PS? I mean, a negative gound using PS and a positive Fuzz using battery?
cheers
If i fart a lot,  it means that i'm a Gas expert ?

jkokura

You can connect pedals using negative voltage together, and pedals using positive voltage together, bt you can't combine them on one powersupply.

Jacob
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RobA

The battery is completely floating with respect to the other power supply until you attach it to a ground point to give it a reference. So, it is fine. What you don't want is two power supply connections that are already referenced to each other somewhere and then try to attach two different voltage levels from these supplies to the same ground.

If you have two (transformer) isolated power taps, that works too. Personally, I like the RoadRage solution because I don't like using batteries and it keeps everything simple.
Affiliations: Music Unfolding (musicunfolding.com), software based effects and Rock•it Frog (rock.it-frog.com), DIY effects (coming soon).

Haberdasher

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Gledison

The roadrage is the next on the list!!!
just one thing I didn't really understand, if the signal coming from a positive supplied pedal (output) is connected to the input of a negative supplied pedal, would not be a trouble?
maybe I need to write it down on a schematics kind of way to understand...
If i fart a lot,  it means that i'm a Gas expert ?

RobA

It won't be a problem because the ground is always the same ground. The RoadRage generates a negative supply and this is what you attach -9V to. But, the ground is the same 0V level throughout both pedals.
Affiliations: Music Unfolding (musicunfolding.com), software based effects and Rock•it Frog (rock.it-frog.com), DIY effects (coming soon).

Gledison

#8
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If i fart a lot,  it means that i'm a Gas expert ?